1. Field of the Invention
The present invention relates to a refrigerator-freezer unit having a machine room for a refrigerator on the lower portion thereof and a cold room for goods to be cooled on the upper portion thereof.
2. Description of the Prior Art
The conventional refrigerator-freezer unit has a machine room on the lower portion thereof for a refrigerator and a cold room on the upper portion thereof in which goods to be cooled are placed and which is usually used as a show case. The unit is typically shaped in a quadrangle in its cross section. The machine room is constructed of a bottom plate, four pillars vertically extending and fixed to four corners of the bottom plate, a reinforcing member connected to the middle portions of the pillars and cover plates attached to the outside surfaces of the pillars. A refrigerator comprising a compressor, a condenser, an expansion means, an evaporator, a blower means and so forth is placed in the machine room. The cold room is constructed of a roof plate, four pillars vertically extending and fixed to four corners of the roof plate, a bottom plate disposed between the cold room and the machine room, three side walls disposed between adjacent pillars and usually constructed from glass, and a door free to open and close and usually constituting one side wall.
The machine room and the cold room are connected to each other and assembled as a single unit by directly connecting machine room pillars and cold room pillars via screws or by welding.
In such a conventional unit, however, although the top portions of the cold room pillars are fixed to the roof plate of the cold room, the bottom portions thereof are merely connected to the top portions of the machine room pillars, respectively. Therefore, the cold room pillars are not very rigid. When an external force operates on the cold room, it may be difficult for the cold room pillars to maintain their parallel relation in the vertical direction and torsion or deflection of the cold room pillars can occur.
On the other hand, the bottom plate of the cold room has an opening through which cold air passes from the machine room to the cold room, and a guide plate is usually disposed on the portion of the opening in order to efficiently circulate the cold air sent from the opening to the inside of the cold room. This guide plate is usually fixed at its bottom portion to the edge portion defining the opening via an appropriate engaging means and fixed at its side portions to cold room pillars via screws.
In such a conventional structure, attaching and removing the guide plate are relatively difficult procedures. The procedures are relatively long since a tool must be used to fasten and unfasten the screws and the cold room is usually not wide enough to provide a sufficiently large working space. Moreover, in the aforementioned structure wherein the rigidity of the cold room pillars is relatively low, it is sometimes difficult to fit the fastening portions of the guide plate to the fastening portions of the cold room pillars due to the torsion or deflection of the cold room pillars.